Extension-table



THO. P. SHERBORNE, OF PHILADELPHIA, PENNSYLVANIA.

EXTENSION-TABLE.

Specification of Letters Patent No. 6,557, dated June 26, 1849.

To all whom t may concern:

Be it known that I, vTHOMAS P. SHER- BORNE, of the city and county of Philadelphia and State of Pennsylvania, have in- E vented certain new and useful Improvements in Expanding Tables, of which the following is a full and exact description, reference being had to the annexed drawings of the same, making part of this specication, in which- Figure l is a perspective view of the table partially extended with the loose leaves or sections of the top and also the top of one of the ends remo-ved, to expose more fully the expanding and adjusting mechanism.

Fig. 2 is a plan of the apparatus for adjusting the levers and holding them at any point to which they may be expanded. Fig. 33 is a section taken through the line of Fig. l. Fig. 5 is a perspective view of one of the joint pins which connect the levers.` Fig. 6 is a section taken through the line 22 of Fig. 5. Fig. 7 is a view of a modified form of the joint pin.

In the accompanying drawings A and B are respectively the two halves of what appears in their ordinary unexpanded condition, a common table, these two halves are connected by a series of levers C, so jointed together that they will expand freely in the direction of the two parts A B, mutually supporting and bracing each other, in order that in expanding and contract-ing they will not bend laterally but cause the two ends to recede and approach in a right line.

lVhen the table is unexpanded the jointed levers are parallel, and in a position across the table nearly parallel to its ends, the joints in the transverse rows being at the greatest distance from each other, and those in the longitudinal rows nearest together. When the table is elongated to its greatest extent the leversassume a position nearly parallel to its sides and the relative position of the joints is reversed, those in the longitudinal row being at the greatestl distance apart, while those in the transverse rows are nearest together. This system of levers is connected to either end of the table by means of a slide hinged to the joint D at the outer end of the first pair of levers, which is placed in a slotted plate attached to the side of the transverse piece E. The pin a of the joint where the first pair of levers cross, has a projection on its head that passes into a groove on the under side of the table top;

this groove is parallel to the sides of the.

table, and of course allows the levers to move the two ends of the table toward or from each other, only in a right line. As no change in the degree of expansion of the table can be made without causing the joints of the levers taken in transverse or longitudinal rows to be moved either nearer to or further from each other, I have taken advantage of this property to devise a convenient Inode of moving the table into any required position, and then holding it there. This device consists of a straight round bar of iron F turning on a central bearing b which prevents it from moving endwise, the bearing being attached to one of the center row of joints, which are always in the middle of the table. This rod F is capable of turning on its axis through an arc o-f about ninety degrees, and has a row of cogs or teeth o on one of its sides which can be turned down into gear with a catcher in the block 0l through which one end of the row passes, the opposite end passing through the block d in which is a pinion e into which the rack takes, this pinion is turned by a lever f having a slot on its end that passes over the square end of the axle of the pinion, this slot allowing the lever to be pushed forward so that the cog on its end will enter one of the spaces between the cogs g or the lever may be drawn back so that the cog on its end will turn inside of the cogs g and by having the teeth of the rod F thrown into gear with the pinion, the system of levers c may either be expanded or contracted by force applied through the lever f; this affords an easy method of drawing up the joints of the top to make them tight, and when tight of securing them so, by pushing the lever f forward between the teeth g to hold it.

When it is required to extend or contract the table with the least obstruction, the teeth of the rod F are turned around so as to be out of gear with the pinion and catches. The pins which pass through the levers to connect them together and form the joints are formed as represented in Figs. 5 and 6, the pivot having a head on one end and a groove n. surrounding it near the other, around which a collet m in two semicircular parts is clasped, each segment being secured to the lever by means of a screw or nail, thus making a very neat, cheap, and durable joint. There may be a pinion to take into either end of the rod F, if it is deemed advisable, in order that the table may be adjusted with equal ease on both sides.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The combination of the projecting pin a and the groove a with the series of jointed levers, whereby the tivo ends of the tables are caused to recede Jfrom7 and approach yeach other in right lines, which insures at all times the accurate meeting and joining of the movable and stationary leaves.

2. The manner of extending or contracting the table, and holding it in any given position by means of the combination of the P. H. WATSON, S. C. DoRsY. 

